1. Field of the Invention
The present invention relates to a control method for an information storage apparatus, an information storage apparatus, a program and a computer readable information recording medium, and, in particular, to a control method for an information storage apparatus having a function of providing redundancy to information stored in the information storage apparatus, the information storage apparatus, a program for causing a computer to carry out the control method, and a computer readable information recording medium storing the program.
2. Description of the Related Art
In an information storage apparatus mounting hard disk drives in such a manner that redundant hard disk drives are provided for the purpose of improving reliability of information stored therein, a redundancy failure may occur in which a hard disk drive providing the redundancy has a light trouble.
For example, as shown in FIG. 1, an information storage apparatus as a computer, called an SVP (service processor) 100′, for managing and controlling a large-scale computer, mounts two hard disk drives HDD#0, 151 and HDD#1, 152, storing an SVP control program 20′ and control data required for achieving a user operation function, a maintenance function, a testing function, a communication function with an external monitoring apparatus and so forth.
The SVP is also provided with an HDD redundancy control part 31′ for managing and controlling these two hard disk drives as resources having a redundant duplicated configuration.
The HDD redundancy control part partitions the two hard disk drives in the identical configurations, and carries out duplicating control in the thus-obtained partition units.
Further, when detecting an un-restorable trouble in one of these two hard disk drives (in the example of FIG. 1, the hard disk drive HDD#0), the HDD duplicating control part switches operation of the partition having the trouble (in the example of FIG. 1, a partition #1) into a non-duplicated control state of using only the normal one of the hard disk drives, and thus, operation of the SVP control program, as a host system, continues in the state.
In this case, the HDD duplicating control part reports the fact that the redundancy of the hard disk drives, i.e., the duplicated state thereof, has thus partially failed, to a maintenance staff.
It is noted that, in the specification and claims, ‘redundancy fails’ or ‘redundancy failure’ means, from a state where information is provided with redundancy, that is, the information is copied, thus a plurality of sets of information each having identical contents are created, and thus, the plurality of sets of information having the identical contents are duplicately stored in a plurality of recording media, respectively, i.e., a redundant state, not all but one of the above-mentioned plurality of sets of information having the identical contents has a trouble so that the redundancy fails.
It is noted that, in such a ‘redundancy failure’, the remaining ones of the plurality of sets of information having the identical contents have no trouble, thus no actual loss in the information has occurred, and thus, merely an expected advantage for security of the information from the redundancy, thus lowers to a corresponding degree.
That is, in the example of FIG. 1, a frequency of occurrences of a situation that such an-restorable trouble also occurs on the hard disk drive on the normal side for the partition, for which partition the duplicated state has thus already failed in the preceding redundancy failure, is low. Accordingly, it may be said that urgency for an actual exchange work of the trouble hard disk drive which is a cause of the above-mentioned redundancy failure, is not so high.
However, it is not preferable that such a state that the redundancy failure is left un-solved for a long period. The possibility that the corresponding partition may have a trouble also in the hard disk drive on the normal side is small, but is not zero. When such a situation that the hard disk drive on the normal side also has a trouble, occurs, the corresponding information may be actually lost, and thus, operation of the SVP may have to be interrupted. Therefore, it is preferable that a maintenance staff rapidly prepares a new hard disk drive and exchange the trouble hard disk drive therefor for a restoration from the redundancy failure, to positively avoid such a serious situation.
On one hand, the large-scale computer, which the SVP monitors and controls, has numerous devices, parts and components, as well as many items to be reported for maintenance, other than the above-mentioned trouble of the hard disk drive of the SVP, and occurrence frequencies of these items to be reported are high.
When a light trouble causing a redundancy failure for a partition is detected in the hard disk drive, this matter is reported to a maintenance staff from the SVP. However, assuming that many other items to be reported having higher priority occur by accident simultaneously, these items are simultaneously reported to the maintenance staff, and thus, the reporting of the above-mentioned light trouble in the hard disk drive may be overlooked.
Japanese Laid-Open Patent Application 2004-271983 discloses a related art.